Application of time reversal for TOA estimation in UWB ranging under dense multipath channel

In most time-based ultra-wide bandwidth (UWB) localization systems, ranging is usually accomplished by the time-of-arrival (TOA) estimation of the first path, which is more challenging in dense multipath channels. This paper proposes a novel time reversal (TR) based method for TOA estimation in UWB ranging. It uses a time reversed version of channel impulse response (CIR) to compensate for the highly cluttered environments. After the time reversed waveform is retransmitted into the same channel, the performance of TOA estimation will be significantly improved by simply search the maximum peak in the output of the receiver. The advantages of TR based method are verified by simulations using the classical IEEE 802.15.4a channel models. Results show that the bias and root mean square error (RMSE) of TR based method are greatly reduced compared to the usually used maximum likelihood method.